神經內科 王志弘
+ 治療或處置的危害 + 環境的危害
+ Systemic review of randomized trials – 單獨一個研究,常常無法顯示出一些少見的不 良反應 + Cohort study + Case control studies + Cross-sectional studies
4 Included Subjects placeboaspirin Myocardial infarction yes no 5 years Randomised to aspirin or placebo Randomized Controlled Trial Longitudinal study
+ Cohort study + Longitudinal study 5 Included Subjects non-smokerssmokers Lung cancer yes no 5 years smoking status measured
+ Case Control Study + Longitudinal study 6 Included Subjects non-smokerssmokers Lung cancer yes no 10 years smoking status measured
+ Cross-sectional study 7 Included Subjects non-smokerssmokers Lung function normal abnormal smoking status measured
Are the results of this harm/etiology study valid?
+ 控制組 + 客觀、或盲化( blind ) – 治療、暴露、結果 + 追蹤: – 時間:是否夠長 – 完整性: lost to follow up ( <20% ) + 因果相關
RCT or cohort Case Control
+ Confounding factor: exposed and non- exposed not randomized + Prospective vs retrospective Retrospective cohort Administrative databases 健保資料庫
+ the outcome of interest is rare or takes a long time to develop – 腫瘤、矽肺病 – 只能使用 case control study + 有些 confounder 無法測量 – Transient – To severe leading to death + The selection of control + Statistical significance, if large number of association factors
+ Exposure and outcome are measured at the same time + case reports of one patient (or a case series of a few patients) – Thalidomide and 海豹肢症 + highlight the need for other studies
+ Blind, objective + Administrative database – 健保資料庫,病歷紀錄 + Patient or doctor recall
+ 統計相關不等於因果相關 + Diagnostic tests for causation – the exposure preceded the onset of the outcome – a dose–response gradient? – dechallenge–rechallenge – the association consistent from study to study + Does the association make biological sense?
Are the valid results of this harm study important?
Magnitude, precision
RCT or cohort Case Control
RCT or cohort
Case Control
+ risks = odds/(1 + odds) + odds = (risk/1 – risk) + ORs and RRs >1 :接觸者得病的機會增加 + ORs and RRs <1 :接觸者得病的機會減少 + 通常 – case control study, OR >4, 認為有意義 – Cohort study, RR>3 就認為有意義 – 還要考慮結果( outcome )的嚴重程度
+
+ Confidence Interval + the adjusted OR for ischemic heart disease or stroke associated with a 25% lower serum homocysteine level was 0.89 with 95% CI 0.83– In our caffeine study, the OR was 2.4 (adjusted for age and smoking) with 95% CI 1.1–6.5.
Can this valid and important evidence about harm be applied to our patient?
研究方法 ? RCT, cohort, case control, cross-sectional